and vessels are similar to a person: Just as for a person, we require his intent for purification, so too for vessels, they are purified only in a case where a person intends for them to be purified.

And if you would say: If the mishna is referring to the case of one who sits and waits to determine when the wave will be detached, what is the purpose of stating this halakha? It is obvious and introduces no novel element.

The Gemara responds that there is a novel element in this halakha. Lest you say: Let us issue a decree that a detached wave does not effect purification due to the concern that otherwise, one would receive the mistaken impression that one is purified in a cascade [ḥardalit] of rainwater containing forty se’a. The halakha is that rainwater purifies only when pooled in one place. Alternatively, let us issue a decree that the edges of the waves, which are in contact with the ground, are ineffective in purifying people and vessels standing on the ground due to the concern that otherwise one would receive the mistaken impression that vessels are purified even if one pushes them upward into the arc of the waves while the water remains airborne. Therefore, the tanna teaches us that we do not issue either of those decrees.

And from where do you say that we do not immerse in the arcs of waves? As we learned in a baraita: One may immerse in the edges of waves, but one may not immerse in their arcs, as one may not immerse in air. Immersion may be performed only on the ground.

The Gemara again asks: But in any event, from where do we derive that non-sacred items do not require intent? The Gemara answers: It is as we learned in a mishna (Makhshirin 4:7): Produce becomes susceptible to ritual impurity only if it is dampened by one of seven liquids and its owner was amenable to its dampening. This is derived from the verse: “But when water is placed on the seed, and some of their carcass shall fall on it, it is impure to you” (Leviticus 11:38). If produce fell into a stream, and one whose hands were ritually impure extended his hands and took the produce from the water channel, his hands are ritually pure through immersion in the stream, and this produce is not in the category of: “But when water is placed.” The produce is not susceptible to ritual impurity because the owner did not intend that his hands become wet.

But if he placed his hands into the stream so that his hands would be rinsed and purified, his hands are ritually pure, and the produce is in the category of: “But when water is placed.” Since he was amenable to the dampening of his hands, the water on his hands renders the produce susceptible to ritual impurity. From the first case in the mishna it is clear that his hands are purified even though his intent was not to immerse them in the water.

Rava raised an objection to Rav Naḥman from a mishna (Ḥagiga 18b): If one immersed for the purpose of eating non-sacred food and assumed the presumptive status of ritual purity for non-sacred food, it is prohibited for him to partake of second-tithe produce. The Gemara infers: If one assumed the presumptive status of ritual purity with regard to non-sacred food, yes, it is permitted for him to eat non-sacred food; if he did not assume the presumptive status, he may not eat non-sacred food. This indicates that even when immersing in order to partake of non-sacred food, one must intend to assume the presumptive status of ritual purity.

Rav Naḥman rejects the proof from the mishna and says that no intent is required to assume the presumptive status of ritual purity in order to eat non-sacred food. Rather, this is what the mishna is saying: Although he assumes the presumptive status of ritual purity for non-sacred food, it is prohibited for him to partake of second-tithe produce.

Rava raised an objection to Rav Naḥman from that same mishna: If one immersed without intent to assume the presumptive status of ritual purity, it is as though he did not immerse. What, is the meaning of the mishna not that it is as though he did not immerse at all?

Rav Naḥman rejects that proof as well. No, it means that if he immersed without intent it is as though he did not immerse to partake of second-tithe produce, but in that case, he immersed for non-sacred food, for which no intent is necessary. The Gemara comments: Rava believed that Rav Naḥman was merely putting him off with his claim that the formulation of the mishna does not conclusively support his objection; he believed that Rav Naḥman was not stating the real meaning of the mishna. Rava then went out, examined the sources, and discovered that it is taught in a baraita explicitly in accordance with the opinion of Rav Naḥman: If one immersed and had no intent to assume the presumptive status of ritual purity, it is permitted for him to eat non-sacred food, but it is prohibited for him to partake of second-tithe produce.

Abaye said to Rav Yosef: Let us say that there will be a conclusive refutation of the opinion of Rabbi Yoḥanan from this baraita. This baraita states that immersion without intent is effective for non-sacred items, while Rabbi Yoḥanan said (31a) that if a woman who is impure due to menstruation immerses without intent she is forbidden to her husband, who is non-sacred.

Rav Yosef said to him: Indeed, the baraita is contrary to his opinion, but Rabbi Yoḥanan is saying his opinion in accordance with the opinion of Rabbi Yonatan ben Yosef.

As it is taught in a baraita with regard to the verse dealing with the purification of a leprous garment, which must be laundered, quarantined for a week, and then immersed in a ritual bath: “And the garment…that you shall wash and the leprosy departed from them, and it shall be washed a second time and shall be pure” (Leviticus 13:58). Rabbi Yonatan ben Yosef says: It would have been sufficient for the verse to simply state: And it shall be washed and shall be pure. For what purpose does the verse state: “A second time”? The Torah juxtaposes the second washing, the immersion, with the first washing, the laundering. Just as the first washing is performed with intent, as it is written: “And the priest shall command that they wash the garment that has the leprous mark, and he shall quarantine it seven days more” (Leviticus 13:54), so too, the second washing, the immersion in a ritual bath, must be performed with intent.

If so, based on the same juxtaposition, perhaps derive: Just as there, with regard to the first washing, we require the intent of a priest, who commands to wash the garment, so too here, with regard to the second washing, we require the intent of a priest. Therefore, the verse states: “And shall be pure” (Leviticus 13:58), indicating that there is purity in any case where there is intent, even without a command from a priest. In the opinion of Rabbi Yonatan ben Yosef, even the immersion of the non-sacred garment must be performed with intent. Rav Yosef states that Rabbi Yoḥanan bases his statement on Rabbi Yonatan ben Yosef’s opinion.

Rav Shimi bar Ashi objects to the association of the statement of Rabbi Yoḥanan with the opinion of Rabbi Yonatan ben Yosef: Did Rabbi Yoḥanan say that immersion of a non-sacred garment requires intent? But doesn’t Rabbi Yoḥanan say that the halakha is in accordance with an unattributed mishna?

And we learned in the mishna: If a knife fell and slaughtered an animal, although the knife slaughtered the animal in the standard manner, the slaughter is not valid. And we discussed it: The reason the slaughter is not valid is that the knife fell. But by inference, if one dropped the knife the slaughter is valid, and that is the ruling even though when dropping the knife he did not intend to slaughter the animal. And we say: Who is the tanna who holds that we do not require intent for slaughter? Rava said: It is Rabbi Natan. Based on his principle that the halakha is in accordance with an unattributed mishna, Rabbi Yoḥanan should rule in accordance with the opinion of Rabbi Natan cited in the unattributed mishna, and not in accordance with the opinion of Rabbi Yonatan ben Yosef.

The Gemara answers: With regard to slaughter, even Rabbi Yonatan ben Yosef concedes that intent is not necessary. He learns this from the fact that the Merciful One revealed that if one acts unawares in performing the slaughter of sacrificial animals, with no intent to slaughter, the offering is disqualified. This is derived (13a) from the verse: “You shall slaughter it to your will” (Leviticus 19:5). By inference, conclude that with regard to the slaughter of non-sacred animals we do not require intent.

While on this subject the Gemara clarifies: And the Rabbis who disagree with Rabbi Natan and hold that slaughter of non-sacred animals requires intent would say: Although we do not require intent to slaughter non-sacred animals, we require intent to cut the neck of the animal. Throwing the knife down is not sufficient.

Rava said that it was with this contention that Rabbi Natan overcame the Rabbis: He said: Is it written with regard to the slaughter of non-sacred animals: And you shall cut? It is written: “And you shall slaughter” (Deuteronomy 12:21). The Torah does not distinguish between cutting and slaughtering; if we require intent for cutting, we should require intent even for slaughtering. Conversely, if we do not require intent for slaughtering, we should also not require intent for cutting.

The Gemara revisits the matter of immersion without intent. What are the circumstances of a menstruating woman who, after the menstrual flow ended, was compelled against her will and immersed in a ritual bath? If we say that another woman compelled her and immersed her in a ritual bath, the immersion should be valid even according to the opinion of Rabbi Yoḥanan, as the intent of another woman is full-fledged intent.

And furthermore, in that case the immersion enables her to partake of teruma as well, as we learned in a mishna (Nidda 13b): In the case of a woman who is a deaf-mute, or an imbecile, or blind, or who went insane, and is therefore unable to examine herself reliably, if one of these women has a competent friend, that friend prepares her by examining her and immersing them in a ritual bath. And on that basis the incompetent woman may partake of teruma.

Rav Pappa said: According to Rabbi Natan, who does not require intent for the slaughter of non-sacred animals, immersion against her will that renders it permitted for a woman to engage in intercourse with her husband is in a case where she fell from a bridge into a river, with no intent at all. According to the Rabbis, who require intent to cut for slaughter to be valid and intent to enter the water for immersion to be valid, it is referring to a case where she descended into the water to cool herself, with no thought of purification.

The Gemara continues its discussion of the dispute between Rabbi Natan and the Rabbis. Rava said: If one slaughtered a red heifer and in the same action slaughtered another animal together with it, everyone agrees that the red heifer is disqualified.